If you are referring to the Fed repo market operations, then these are short-term collateralised loans, so not really the same thing as pumping trillions in to the real economy.
A fiscal stimulus of that size would almost certainly drive demand (during a pandemic that has caused a negative supply shock) and therefore increase inflation.
The Cantillion effect describes a phenomena of relative inflation due to the uneven distribution of new money and access to credit.
This doesn't really translate to "a flow of wealth from working classes and savers to the bankers and the managerial class". Rather, the impact on inequality is that it reduces the purchasing power of those not benefiting from the increased supply of money and credit. As these tend to be the poorest individuals in society, inequality is made worse.
To be clear, I am in no way advocating the view that it is "inevitable that everything in banking/finance will move to a decentralized model". Financial institutions, although not perfect, serve many function which would not be suited to a decentralised model. There is no dichotomy here between traditional banking and decentralised finance.
There is however no reason for banks to have a monopoly on these services and every reason to encourage decentralised systems to develop. You claim that people don't want autonomy when this is clearly untrue. It's easy to assume this if speaking from a position of privilege, however there are more than a few edge cases where autonomy is required. A dissident in HK, an anonymous donor in Turkey, a worker in Venezuela, or perhaps even someone in the West wishing to make an international payment but not wanting to wait 2-5 days for a SWIFT payment to clear whilst also incurring a number of handling and transaction fees.
To dismiss something as 'meaningless utopianism' just because it doesn't agree with your personal experience is incredibly naive and shortsighted.
There are plenty of legitimate reasons for wanting a decentralised alternative to banking. Just recently there was an article posted on here about how money is used as a system of control. [0] Even under the best case scenario of well regulated financial institutions in a functioning democracy there is still little recourse/accountability if these institutions or the government decides to freeze your accounts. [1]
A fiscal stimulus of that size would almost certainly drive demand (during a pandemic that has caused a negative supply shock) and therefore increase inflation.